I also use a Redding the body die to bump the shoulder and resize the case a minimal amount. To set it up for a .002" bump on the shoulder I use the following procedure.
1. I take a case fire formed in my firearm. The case should be a tight fit so that it's as close as possible to chamber dimensions.
2. Set the case in the Digital Headspace Gauge and zero the gauge. Here's the link: Innovative Technologies - Reloading Equipment
3. Insert a .003" shim on the redding body die and screw the die in the press till it's snug on the shellholder. Here's the link for the set of shims:
- Skip's die shim kit - (7/8-14)
4. Resize the case with that set up.
5. Place the case in the Digital Headspace Gauge and get a measurement of the amount of shoulder bump.
6. If the bump measures .005" all you need to do is replace the .003" shim with a .006" shim and you get a .002" bump.
The beauty of this set up is that you don't need to touch the die even if you have multiple guns of the same caliber - you just change the shim in accordance with the bump you need. Also you can use another shim if you want more or less bump.
Occasionnally, you get a minimal dimension chamber where you can only get .001" or less with the body die. When this occurs, I use a dedicated shell holder which I sand on a flat surface to take off .001" or so.
Finally it's a good idea to keep a tight fitting fire formed case in your die box to test your setting with the Headspace Digital Gauge occasionnally.
Much of what I describe here can be applied to a regular full length die.